Keep Voronoi texture look during Cell Fracture
The easiest solution is to use UV coordinates.
After fracturing the UV map is separated for each 'shard' and the texture stays in place.

The main downside are 'seams' along the edges of the original UV map.


For seamless look:
Use an empty to  control the Voronoi texture :).

Add an Empty in the same place as your sphere
Change the Texture coordinates to Object &gt; Empty
Now fracture your sphere, and the texture will stay the same

Now bake the result for each individual shard.

One solid sphere. One fractured sphere. Each has it's own empty, textures look the same